North Wales Police and North Wales Fire and Rescue Service have issued a joint safety warning as extreme temperatures grip the region, urging the public to avoid swimming in open water despite the temptation of the warm weather.

With an unprecedented week of heat expected across North Wales, officials say quarry pools, rivers and lakes may appear inviting but can pose serious and potentially life-threatening risks.

Superintendent Simon Barrasford said rising temperatures often lead to an increase in risky behaviour around open water.

“We appreciate the weather is warm and the forecast for this week expects temperatures to rise further, and it can be very tempting to jump into quarry pools as well as rivers and lakes to cool down on a hot day,” he said.

“However, open water can contain hidden hazards such as debris, weeds, and reeds that you may not be able to see from the surface.

“The water can also be very deep, and swimmers can easily find themselves out of their depth. If you are thinking about going swimming in open water, please think again and consider the dangers.

“We urge you to look out for your friends, avoid swimming or jumping into open water and plan how else you can cool off safely.”

Officials also warned of the risk of cold water shock, which can occur even in summer. Sudden immersion in cold water can trigger involuntary gasping, breathing difficulties and cramp, which can quickly lead to panic and drowning, even among strong swimmers.

North Wales Fire and Rescue Service’s Head of Fire Safety, Paul Kay, echoed the warning, stressing the importance of education and prevention, particularly among young people.

“While open water may appear tempting during warm weather, I’m urging people to avoid swimming in lakes, canals, and other unsupervised bodies of water, as hidden hazards can pose serious risks,” he said.

“It is especially important for parents and guardians to talk to their children about the dangers of open water. Teenagers in particular may be more likely to venture out with friends and underestimate the risks involved in using open water to cool down, which can have serious and potentially tragic consequences.”

He urged people to seek safe alternatives and make use of official safety advice.

“Help keep yourself and others safe and well by checking out the latest advice from our partners at Public Health Wales – together we can help protect our communities.”

The public is also encouraged to familiarise themselves with the RNLI’s “Float to Live” guidance, which explains what to do if someone accidentally falls into deep water.

Anyone who witnesses people swimming in quarry pools or other unsafe locations is urged to contact North Wales Police immediately on 999. In coastal emergencies, the public should ask for the coastguard.

Authorities say the message is clear: while the weather may be hot, open water is not a safe way to cool down, and a moment of risk-taking can have devastating consequences.